Question: Solve for $x$ : $30 = -19 + x$
Solution: Add $19$ to both sides: $ \begin{eqnarray} \\ \hphantom{30 {+ 19}} &\hphantom{=}& \hphantom{x} \\ 30 &=& -19 + x \\ \\ {+19} && {+19} \\ \end{eqnarray} $ $ \begin{eqnarray} \\ 30 {+ 19} &=& x \\ \end{eqnarray} $ Simplify. $ x = 49$